Clinical value of stereotactic body radiotherapy for the treatment of metastatic pancreatic cancer

Objective To discuss the clinical value of stereotactic radiotherapy for the treatment of metastatic pancreatic cancer. Methods Data of 17 patients with metastatic pancreatic cancer were retrospectively studied. All patients were admitted to Air Force General Hospital from January 2006 to December 2014. Lung carcinoma was the most common primary tumor (n=7), followed by cystic carcinoma (n=3), esophageal cancer (n=1), gastric carcinoma (n=1), renal carcinoma (n=1), colon carcinoma (n=1), acute myeloid leukemia (n=1), left chest fibrous histiocytoma (n=1), and upper extremity synovial sarcoma (n=1). There were 8 patients choosing the therapy of body gamma knife, 5 choosing the therapy of IMRT, 3 choosing the therapy of 3DCRT and 1 choosing the therapy of TOMO. Metastases median maximum diameter was 3.6 cm (range, 1.6-1.7 cm), median target volume was 37.1 mm3 (range, 11.1-72.1 mm3) and median GTV dose was 50 Gy (range, 40-70 Gy). Patients treatment time was 14 to 22 days, 5 fractions/week and median single dose was 3 Gy. Results Of all the patients of this group, 4 patients qualified as complete remission (CR), 8 patients reached the standard of partial remission (PR), and 2 patients maintained the situation of stable disease (SD). The total percentage of therapeutic efficiency was 70.1 % (12/17). As for the analgesic therapy, 3 patients qualified as CR, 5 patients reached the standard of PR, and 1 patient maintained the situation of MR (minimal response). The total percentage of analgesic therapeutic efficiency was 100 %. The local control rates for six-month and 1 year were both 100 %, and the overall survival rates for 1 year and 2 years were 35.3 % and 5.9 %. No Grade 3 or more acute and late radiation reaction was observed. Conclusion The majority of patients with pancreatic metastatic carcinoma have lost the opportunity to have surgery, but the stereotactic radiation therapy can improve the quality of life and local control rate with small toxicity and acceptable complications. Key words: Pancreatic neoplasms; Metastatic/Stereotactic; Radiotherapy; Prognosis